1. Field of the Disclosure
The present disclosure discloses a method and composition for detecting the presence of antibodies in human or animal bodily fluids (blood, serum, plasma, urine, colostrum, milk, tears, or saliva) to analytes such as bacteria, Chlamydiae, Rickettsiae, protozoa, allergens, autoimmune antigens, viral proteins, and carbohydrates by lateral flow techniques.
2. Description of the Prior Art
Over the years, numerous patents have been issued involving immuno-chromatographic devices. The standard features of these devices comprise the following:
a) A plastic or paper housing allowing the viewing of a reaction area on a bibulous (lateral flow) strip;
b) an opening at one end of the housing allowing for the addition of sample (urine, blood, plasma, serum or bacteria in a media base);
c) Bibulous material (the lateral flow strip) having immobilized specific binding members (analytes) capable of reacting with antigens or antibodies.
d) A pad of absorbent bibulous material (the absorbent pad) enclosed at the end opposite the sample well and used to absorb transversely flowing sample, buffers and colloids;
e) A strip of bibulous material used in the sample well end to initially absorb the sample being applied;
f) A strip of bibulous material in contact with the sample well material and the lateral flow strip and containing a dried colored solid phase reagent, the solid phase coated with proteins or haptens.
Two types of chromatographic immunoassays are commonly described. In the one, proteins, haptens, or small molecule analytes contained in bodily fluids (urine, blood, plasma, serum, and saliva) are detected. The analytes include hCG, FSH, LH, CKMB, TSH, troponins, myoglobulin, cancer proteins, viralbacterial proteins, haptens, therapeutic drugs, and drugs of abuse.
In the other chromatographic immunoassay, the analyte being detected is (are) human antibody (antibodies) of various classes specifically reactive with agents such as viral or bacterial proteins (HIV, Hepatitis A and C, H. pylori, EBV, Rubella, CMV, HSV, Dengue fever, Lyme, Chagas, TB, Toxoplasma, autoimmune antigens, etc.) or allergens (pollens, molds, dust/mites, foods, animal epithelia, etc.). The various analytes are abbreviated VB for simplified use below. When it comes to detecting antibody, three formats are typically used:
1) The colored solid phase [SP] is coated with proteins or lectins [protein A, protein G, lentil lectin, jacalin, concanavilin A, mannan binding protein, wheat germ lectin, peanut lectin and avidchrom] that react with human IgG antibodies. The solid phase may be coated with anti-immunoglobulins that specifically react with IgG, IgM, IgA, or IgE contained in the sample to be analyzed. The bibulous strip would in this case contain the analyte of interest to which the specific antibody contained in the sample reacts.2) The colored solid phase contains the analyte to which the human immunoglobulins react. The bibulous strip would in this case also contain the analyte of interest to which the specific antibody contained in the sample reacts.3) The colored solid phase contains the analyte to which immunoglobulins react. The bibulous strip contains proteins directed against various classes of immunoglobulins or substances such as protein A, protein G, lectins, lentil lectin, jacalin, concanavilin A, mannan binding protein, wheat germ lectin, peanut lectin and avidchrom or a mix of antibody to immunoglobulin classes IgG, IgA, IgM and IgE.
U.S. Pat. No. 5,459,041 (Blaser et al.) discloses antigenic compositions for use in diagnostic kits and the like for detecting the presence of antibodies specific for Campylobacter pylori, Samples of bodily fluids, for instance, may be contacted with immobilized antigen on a solid phase which is then washed and tested for the occurrence of significant levels of antigen/antibody complex. Levels exceeding a predetermined positive threshold are indicative of antibodies to Campylobacter pylori in the sample tested. Kits employing the antigenic compositions of the disclosure preferably include means for detecting the antigen/antibody complex such as materials and reagents for conducting an enzyme-linked immunosorbent assay, Western blot technique, ELISA, liposome-based assay or other known detection tests. The Western blot and ELISA tests used here are for the detection of IgA and IgG antibodies.
U.S. Pat. No. 5,567,594 (Calenoff) discloses a library of isolated and purified antigens specific for a microorganism is a set of individual molecules. The library forms antigen-antibody complexes useful in the context of diagnosing and treating conditions associated with a specific microorganism such as H. pylori-induced gastro-duodenal disease. Antigen-antibody complexes with IgA, IgG and IgM are also useful if the antigen is a bacteria. By this multivariate approach, a specific condition is diagnosed with high sensitivity and specificity by determining whether complexes form between a specific antigen library and a biological sample which contains immunoglobulins from an individual. Such libraries also are useful for immunotherapy. Western blot is used to detect IgE antibodies. The method requires enzyme conjugates and enzyme substrates and two wash steps to detect antibodies.
U.S. Pat. No. 5,420,014 (Cripps et al.) discloses a method for detecting a current infection by H. pylori in a mammal. The method comprises contacting a mucous secretion [saliva] from said mammal with an immobilized antigen component from H. pylori for a time and under conditions sufficient for an IgG antibody in said mucous secretion specific to a antigen component to form a complex therewith and then subjecting said complex to a detecting means which involves an enzyme conjugate and specific substrate.
U.S. Pat. No. 6,068,985 (Cripps) discloses a method which uses saliva to detect IgG in both the Western Blot and ELISA tests. This detection method requires the use of an enzyme conjugate and enzyme substrate and two wash steps to detect the antibody.
U.S. Pat. No. 5,846,751 (Pronovost et al.) discloses a sensitive and specific antigen preparation for the detection of Helicobacter pylori in biological samples. The preparation uses a range of antigens derived from size exclusion chromatography of detergent-solubilized H. pylori cells and the purified antigen preparation is coated on the solid phase. Serological assays such as ELISA, latex agglutination, and rapid EIA assays are used to detect antibodies to H. pylori. The disclosure also uses a lateral flow device to detect total immunoglobulins to H. pylori. In this case, the H. Pylori antigen is striped on the membrane reaction area and also coated to the colored solid phase. The antibody in the sample reacts first with H. pylori gold coated conjugate, and then travels to the membrane reaction area where it reacts with striped H. pylori. 
U.S. Pat. No. 5,200,344 (Blaser et al) uses a purified p28kd protein from H. pylori to detect IgA, IgM and IgG antibody in ELISA and Western Blot. The test requires conjugate and enzyme substrate and two wash steps to detect the antibody.
U.S. Pat. Nos. 6,060,326 and 5,945,294 (Frank et al.) discloses methods to detect canine IgE using a canine Fc epsilon receptor to detect canine IgE antibodies in a biological sample from a canine.
U.S. Pat. No. 5,547,833 (Dorval et al.) discloses a radial flow assay delivery device, and methods of use.
U.S. Pat. No. 5,622,871 (May et al.) discloses an analytical test device useful for example in pregnancy testing, includes a hollow casing constructed of moisture-impervious solid material, such as plastics materials, containing a dry porous carrier which communicates indirectly with the exterior of the casing via a bibulous sample receiving member which protrudes from the casing such that a liquid test sample can be applied to the receiving member and permeate therefrom to the porous carrier, the carrier containing in a first zone a labelled specific binding reagent is freely mobile within the porous carrier when in the moist state, and in a second zone spatially distinct from the first zone unlabelled specific binding reagent for the same analyte which unlabelled reagent is permanently immobilised on the carrier material and is therefore not mobile in the moist state, the two zones being arranged such that liquid sample applied to the porous carrier can permeate via the first zone into the second zone, and the device incorporating an aperture in the casing, enabling the extent (if any) to which the labelled reagent becomes bound in the second zone to be observed. Preferably the device includes a removable cap for the protruding bibulous member. Additionally, May teaches that all of the reagents, analyte reactions, and complexes occur within a single test strip.
U.S. Pat. No. 6,485,982 (Charlton) discloses a test cell and a method for detection of a preselected ligand in a liquid sample such as a body fluid. The test cell includes an elongate outer casing which houses an interior permeable material capable of transporting an aqueous solution and defining a sample inlet, a test volume, and a reservoir volume. The reservoir volume is disposed in a section of the test cell spaced apart from the inlet and is filled with sorbent material. The reservoir acts to receive liquid transported along a flow path defined by the permeable material and extending from the inlet and through the test volume. In the test volume is a test site which includes a first protein having a binding site specific to a first epitope of the ligand immobilized in fluid communication with the flow path. The test site can be observed through a window of the casing. Like May, this patent teaches that all of the reagents, analyte reactions, and complexes occur within a single test strip.
U.S. Pat. No. 6,528,325 (Hubscher et al.) discloses a method and composition for detecting the presence of class specific antibodies reactive with analytes such as bacteria, allergens, autoimmune antigens, viral proteins, and carbohydrates by lateral flow techniques. In one embodiment of the invention, a test sample obtained from bodily fluids reacts with a gold labeled antigen. The resulting complex travels across the membrane, and along the lateral flow strip. Red colored lines formed in specific locations along the test strip where anti-class specific antibodies have been immobilized indicate the presence of class specific antibodies in the test specimen. In another embodiment of the invention, the lateral flow assay serves as an immunochromatographic screening test for the detection of allergen-specific IgE antibodies in human serum. Test sample reacts with gold labeled anti-IgE antibody. The resulting complex travels across the membrane where immobilized allergens capture the allergen specific IgE-anti-IgE complex. Colored lines are formed in the test areas to indicate the presence of allergen-specific IgE antibodies.